Compositional evolution of the emplaced fuel source in the vadose zone field experiment at Airbase Verløse, Denmark

A field experiment was performed in a sandy vadose zone, studying the fate of an emplaced fuel-NAPL source, composed of 13 hydrocarbons and a tracer. The UNIFAC model was used to testthe nonideal behavior of the source, and the numerical model MIN3P was used for assessing the effect of biodegradation on source evolution. The diffusive loss to the surrounding vadose zone and the atmosphere created temporary gradients in mole fractions of the individual compounds within the source NAPL. The evolution of the source composition corresponded in general with expectations based on Raoult's Law, with the exception thatthe mole fractions of aromatic compounds in the source NAPL decreased faster than fractions of aliphatic compounds of similar volatility. Calculation of activity coefficients (y) using the UNIFAC model implied nonideal conditions, with composition-dependent gammas different from 1. Positive deviations were calculated for the aromatic compounds. The effect of biodegradation on source depletion, evaluated by numerical modeling, was greater for the aromatic as compared to the aliphatic compounds. Hence, the faster depletion of the aromatic relative to aliphatic compounds of similar volatility is both a result of the nonideality of the mixture and a result of partitioning and biodegradation in the pore-water. Vapor concentrations of the compounds in the source were in reasonable agreement with predictions based on the modified Raoult's Law with the UNIFAC predicted gammas and the NAPL composition for the most volatile compounds. For the less volatile compounds, the measured vapor concentrations were lower than predicted with the largest deviations for the least volatile compounds. This field experiment illustrated that nonideal behavior and bioenhanced source depletion need to be considered at multicomponent NAPL spill sites.     

Improved CD control and line edge roughness in E-beam lithography through combining proximity effect correction with gray scale techniques

A proximity effect correction (PEC) technique for E-beam lithography is presented which overcomes hardware limitations of many older E-beam writers regarding the number of physical dose classes by a unique combination of gray scale techniques with PEC using the Layout BEAMER software. The benefit is not only an improvement in critical dimension control, but also an improvement in line edge roughness (LER). Compared to standard PEC techniques the percentage line width deviation has been dramatically reduced by more than a factor of three.     

Chemical degradation kinetics of recombinant hirudin (HV1) in aqueous solution: effect of pH

PURPOSE: To gain information on the chemical stability pattern and the kinetics of the degradation of recombinant hirudin variant HV1 (rHir), a thrombin-specific inhibitor protein of 65 amino acids, in aqueous solution as a function of pH. METHODS: Stability of rHir was monitored at 50 degrees C in the framework of a classical pH-stability study in aqueous buffers pH 1-9.5. Two capillary electrophoresis (CE) protocols were used: one for the kinetics of succinimide formation at Asp53-Gly54 (C-terminal tail) and Asp33-Gly34 (loop section), the other for the kinetics of rHir degradation. To check for potential effects of conformational changes by thermal denaturation, circular dichroism (CD) measurements were performed between 25 and 80 degrees C. RESULTS: Throughout the pH range studied no effect of thermal denaturation on rHir confirmation at 50 degrees C was observed. rHir was most stable at a neutral pH whereas, at slightly acidic pH, an intermediate stability plateau was found. Both, strongly acidic and alkaline conditions led to fast rHir degradation. Depending on the pH of degradation, rHir was found to degrade in various combinations of multiple parallel and sequential degradation patterns. Special focus was on succinimide formation at Asp53-Gly54 (C-terminal tail) and Asp33-Gly34 (loop) and on the potential of isoAsp formation in position 53 and 33. CONCLUSIONS: Chemical rHir stability in the intermediate pH range depends strongly on succinimide formation. At slightly acidic conditions succinimides represent the major degradation product (up to 40%). Around neutral pH succinimides react further, presumably by isoAsp formation, and concentrations remain low. Relative preference of succinimide formation in the C-terminal tail domain versus the loop domain is explained by higher backbone flexibility in the tail.     

Usefulness of FDG-PET in diagnosing primary lymphoma of the liver

This case report shows for the first time the usefulness of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) in the diagnosis of primary non Hodgkin's lymphoma of the liver. Results of FDG-PET, which in contrast to other imaging techniques offers the advantage of screening the whole body, demonstrated a high glycolytic activity of a solitary mass in the liver with central necrosis (loss of glycolytic activity), but no spread of lymphoma to the body. These results were confirmed by ultrasound, computed tomography, magnetic resonance imaging and were biopsy proven. From our findings we conclude that in patients with liver masses with high uptake of FDG, lack of liver dysfunction and absence of signs indicating other malignancies, a primary lymphoma of the liver should be considered as a possible diagnosis.     

Bendamustine as salvage treatment in patients with advanced progressive breast cancer: a phase II study

A phase II pilot study of bendamustine as salvage treatment in patients with advanced breast cancer was performed to determine the objective response rates and make further observations on the toxicity of this drug. A group of 37 patients, pretreated with chemotherapy for advanced disease, entered the trial. Treatment consisted of 150 mg/m2 bendamustine on days 1 and 2 of a 4-week treatment course. Patients continued to receive treatment until complete remission and then two further courses, until tumour progression or unacceptable toxicity ensued. A total of 36 patients received at least one treatment course and were assessable for toxicity; 33 patients were evaluable for treatment results. Dose-limiting grade 3 and 4 WHO toxicity occurred in 5 and 3 patients respectively; 27% of patients entered complete or partial tumour remission. The median time to tumour progression was 2 months with a range of 1-14 months. The efficacy of bendamustine was apparently independent of pretreatment with anthracyclines, suggesting a lack of cross-resistance between bendamustine and anthracyclines. It can be concluded that bendamustine in the dose and application schedule used here is active in the salvage therapy of women with advanced breast cancer. The toxicity was acceptable. Future studies have to confirm the data of this pilot trial and to define the role of bendamustine in the combination chemotherapy of metastatic breast cancer that has been suggested by previous trials.     

Some Results on Effective Randomness

We investigate the characterizations of effective randomness in terms of Martin-Lof tests and martingales. First, we address a question of Ambos-Spies and Kucera, who asked for a characterization of computable randomness in terms of tests. We argue that computable randomness can be characterized in terms of Martin-Lof tests and effective probability distributions on Cantor space. Second, we show that the class of Martin-Lof random sequences coincides with the class of sequences that are random with respect to computable martingale processes; the latter randomness notion was introduced by Hitchcock and Lutz. Third, we analyze the sequence of measures of the components of a universal Martin-Lof test. Kucera and Slaman showed that any component of a universal Martin-Lof test defines a class of Martin-Lof random measure. Further, since the sets in a Martin-Lof test are uniformly computably enumerable, so is the corresponding sequence of measures. We prove an exact converse and hence a characterization. For any uniformly computably enumerable sequence r₁, r₂,... of reals such that each r_n is Martin-Lof random and less than 2^-n there is a universal Martin-Lof test U₁, U₂,... such that U_n{0,1}^∞ has measure r_n.